As the prior art reciprocating internal combustion engines change the reciprocation into circular motion, they have the disadvantages of unstable torque moment, great internal force, bulky, great power conversion loss and difficult manufacture.
To solve these problems, the Wankel engines and those recommended in the Chinese patents 87104050A, 87103815, 88102309.4 and 88207749.6 have made some attempts, but they have not achieved satisfactory results, because one or some of the following problems exist in each of those engines.
1. The compression ration is not high, so that the efficiency of the combustion engine is low and is uneconomical in use.
2. Incompatibility of the fuel in the combustion engine, especially such fuel as diesel oil of low volatility.
3. There is no such output power range as can be comparable with the reciprocating engine.
4. The structure is complicated, the processing is difficult and the abradability is not adequate.